Re: [SR-Users] Same Via Tag for INVITE and ACK on S/L loadbalancer

In such case, because the proxy is doing stateless forwarding, there is no transaction. I guess the solution right now is to use tm for relaying - is any concern of doing that? If someone wants to look at generating same via branch, I am fine with it, eventually controlled by a parameter if the code change is significant, to be able to switch to current mode if unexpected side effects pop up. One more note in this case: I expect it would be required to generate different tag for 200ok ACK, so it is matched as different transaction by next hop, not sure if there is any easy way to discover the type of ACK in a stateless proxy. I am not sure I remember correctly, but in some discussions I think it was suggested to just reuse the branch value of incoming top Via when doing stateless forwarding. Cheers, Daniel On 10.02.20 16:26, Sebastian Damm wrote: >  We use 5.2 on the affected systems. > >  On Mon, Feb 10, 2020 at 4:15 PM Serge S. Yuriev <me(a)nevian.org> wrote: >>  Hi >> >>  I believe you are using 5.2 or 5.3 series? This tend to work >> properly on 5.1 series >> >>  10.02.2020, 18:10, "Sebastian Damm" <damm(a)sipgate.de>de>: >>>  Hi, >>> >>>  actually, our only problem is handling negative replies. The ACK >>>  belongs to the same transaction and therefore has to carry the >>> same >>>  Via branch ID. >>> >>>  Sebastian >>> >>>  On Mon, Feb 10, 2020 at 3:50 PM Yuriy Gorlichenko <ovoshlook(a)gmail.com> wrote: >>>>   ACK for successull response is a new transaction. It has to be different. May be it is better to point provider to this? >>>> >>>>   On Mon, 10 Feb 2020, 14:26 Sebastian Damm, <damm(a)sipgate.de> wrote: >>>>>   Hi, >>>>> >>>>>   I stumbled upon an interop problem with a carrier. We have the >>>>>   following scenario: >>>>> >>>>>   Gateway --> Loadbalancer --> Carrier >>>>> >>>>>   The loadbalancer generates a Via header for each request. But >>>>> since it >>>>>   is stateless, the Via tag is generated for each request. As a >>>>>   consequence, the Via tag in the ACK differs from the one in the >>>>>   INVITE. And one carrier doesn't handle those ACKs if the Via >>>>> tag >>>>>   differs. >>>>> >>>>>   Is there a way to force the creation of a "deterministic" Via >>>>> branch >>>>>   tag? For example, building it from a hash over call-id and >>>>> from-tag or >>>>>   something like that?